How to use the discount calculator
Enter the original price and the percentage off. If there is a second offer on top, such as a coupon code on a sale item, put it in Extra discount. Add the tax rate if tax is charged at the till rather than shown on the label.
Two discounts are taken one after the other, so 20% off and then 10% off is 28% off in total, not 30%.
The formula
Sale price = price × (1 − discount ÷ 100)
A second discount is applied to the already reduced price. Tax, if any, is added last.
Worked example
An 80 pair of shoes at 25% off costs 80 × 0.75 = 60, a saving of 20.
Common questions
Is 50% off plus another 50% off free?
No. The second half is taken from the already halved price, leaving a quarter of the original to pay.
How do I find the original price from a sale price?
Divide the sale price by (1 − discount ÷ 100). A 60 item at 25% off was 60 ÷ 0.75 = 80.
Is tax worked out before or after the discount?
After, in most places. A shop discount lowers the price that the tax is charged on.